If bacteria die where do their corpses go? When something is sterilized through gases, steam or heat, it kills the bacteria but the little bacteria corpses are still there. This concept is especially important when it comes to sterilizing medical instruments. The dead byproducts of bacteria are called “pyrogens” because they cause (among other things, such as death) fevers. Surgery instruments have to go through a process known as depyrogenation to get rid of the tiny bacteria corpses. (Source)